Fighting between a community of cattle herders and farmers over land and water has killed 12 people in Kenya's south-east, the Kenya Red Cross said.
The two communities periodically clash over resources but this incident may also have been politically instigated because it fits a pattern of violence which has occurred in three previous elections, according to the Red Cross. Kenya will hold elections in six months.
The Kenya Red Cross said another 10 people were wounded in the fighting in Tana River delta, near where more than 52 people from the Orma tribe of semi-nomadic cattle herders were killed late last month by members of the Pokomo tribe of farmers.
Mohammed Morowa, a Pokomo, said 11 of those killed in the dawn attack were his relatives and that the killing was retaliation by members of the Orma tribe over the killing of their community members last month.
Mr Morowa said tens of grass thatched houses were burned at Chamwanamuma village region. The attackers used guns, arrows and machetes.
More than 200 people have died since January in several separate clashes that follow the pattern of pre-election violence that Kenya has suffered in most elections since the early 1990s, the Kenya Red Cross said.